Oak

🌳 Outdoor LoRa-GPS tracker with E-Ink display 🔑

power 18650

wireless LoRa,

sensor GPS, E-Ink

mcu SAMD21G18

bom items 82

bom cost USD $78.93

vendors 6

completed July 2022

Start
Code
PCB
Case
Bill of Materials
Design
Power
CSQ
Resources

Power overview

Power source

4200mAh 18650 button-top battery

Battery life

14 hours

Charging duration

14 hours

Just plug in the USB cable to the Oak PCB that has the 18650 battery in the holder at the back. RED Charging LED will light up when charging. The battery will be fully charged when the RED Charging LED turns off.

Charging the battery

The multimeter with data logging feature was hooked up to the test points of VBAT and GND. It took about 11 hours to fully charge the battery with the on-board charging circuit.

Measuring battery life

Two types of firmware was uploaded to measure the longest possible and shortest possible battery life:

Longest possible: Blinky LED was 19 hours
Shortest possible: Demo was 14 hours